Field of the Invention
The present invention relates to an image processing apparatus and an image processing method, in particular, for adjusting a color conversion table on the basis of a signal value corresponding to a color that is visually selected as a target color from a printed chart.
Description of the Related Art
In recent years, electrophotographic apparatuses that achieve image quality comparable to that of printing machines have appeared with their improvement in performance. Printing for, for example, point of purchase (POP) advertising used in stores can therefore be more easily performed at each store. The POP advertising is performed for sales promotion. In the printing for the POP advertising, an output may be printed with a color different from that of a sample because of a difference in printing apparatus or a difference in print timing. In this case, for example, a service person with expert knowledge has performed color matching by adjusting the apparatus. However, in recent years, there have been implemented systems with which, for example, a person in charge in a store can easily perform color matching even if the person has no special expert knowledge. In such a system, for example, a color desired to be adjusted is extracted from an image of a POP display and patches of respective neighboring colors of the extracted color are generated. Subsequently, a chart in which the generated patches are arranged is printed, and a user visually selects the patch of a desired color from the printed patches. A table for color conversion is adjusted in accordance with the color of the selected patch (see Japanese Patent Laid-Open No. 2011-114717).
There is a case where a plurality of colors are adjusted using such a system. In this case, the number of times of adjustment corresponds to the number of colors desired to be adjusted. In a case where a color adjustment is performed a plurality of times, a single color conversion table is adjusted a plurality of times corresponding to the number of colors desired to be adjusted. Each time a single color is adjusted, a color conversion table is stored as the history of an adjustment result. This makes it easy to change a past color adjustment result. For example, after color adjustments have been performed in the order of color 1, color 2, and color 3, only an adjustment result of the color 1 can be easily canceled. However, a color conversion table obtained after the adjustment of the color 2 includes the adjustment result of the color 1. Therefore, in a case where the adjustment result of the color 1 is canceled, the amount of adjustment of the color 1 is also canceled from the color conversion table obtained after the adjustment of the color 2. The same thing can be said for a color conversion table obtained after the adjustment of the color 3. That is, in a case where an adjustment result of a certain color is canceled, the amount of adjustment of the color is also canceled from a color conversion table obtained at the time of a subsequent adjustment. Japanese Patent Laid-Open No. 2008-219422 discloses a technique for canceling all of adjustment results of a color conversion table stored as histories and performing the same adjustments of colors other than a color desired to be canceled again upon a color conversion table. For example, in a case where only an adjustment result of color 1 is canceled after color adjustments have been performed in the order of the color 1, color 2, and color 3, all of the adjustment results of the colors 1 to 3 are canceled and the adjustments of the colors 2 and 3 that are the same as those performed in the past are then performed upon a color conversion table.